Franklin Mayor and Aldermen to Vote on Extensive Floodplain Alteration Proposal on Harpeth- Brownland Farm- ATTEND PUBLIC HEARING 9/17/2021

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Urge Franklin Aldermen Board to Follow staff and Planning Commission Recommendation to Deny this 471-unit High Density Residential Subdivision on Brownland Farm/Christ Community Church.  

YOUR ATTENDENCE- IN PERSON- WILL HAVE THE MOST IMPACT

7pm Tuesday, 9/14 public hearing, 109 3rd Avenue South, Franklin.  

Also send a brief email:  recorder@franklintn.gov by  Monday evening, September 13.  Click here for direct emails to the mayor and aldermen.   

The proposed development is in a uniquely challenging bend in the Harpeth River because the high density residential development proposal will be surrounded by floodwaters.  As seen in the map below, floodwaters cut across this bend and inundate Hillsboro Road to the north and south of the proposed development entrances cutting off the only way in and out. This creates an important public safety risk.  

The development proposal involves altering 80% or more of the property that is currently natural floodplain to maximize development without improving any of the flooding issues on Hillsboro Road to reduce safety risk.  Nor does the floodplain alteration proposed reduce flooding risks just downstream where large residential subdivisions (Fieldstone Farms and others) have numerous homes now in the 100-floodlplain that were not when approved over 20 years ago.   This is very likely the most extensive floodplain alteration proposal the city of Franklin has seen in many years.  

Map from development proposal. HC added floodwater depth information and notes in boxes.

1. Public safety issue with floodwaters on existing roads

  • At 1 to 4 feet deep(see map above), floodwaters on all existing roads are significantly ABOVE the city requirements that new development provides an emergency bypass for a 100-year flood and that existing and critical service roads not have more than 3 inches of floodwaters over more than half the road.   (Section 23-106 (2) implementation, (e) stormwater design requirements p. 13). (See below for FEMA maps and elevation information.)
  • For a floodplain and floodway fill proposal like this (see map above) to go to FEMA for the required review, the city completes a form that states that the proposal meets all city floodplain management requirements. This proposal does not because of the high floodwater depths on Hillsboro Road

2. The floodplain alteration is extensive and directly conflicts with the city’s Envision Franklin Plan

  • As city staff stated in the recommendations to deny both the rezoning and development plan, the Envision Franklin land use plan specifically states “the preservation of floodplains has a direct public safety purpose and helps to minimize property damage during flooding.  Disruption should be limited to preserve form and function.”
  • The proposal does NOT “improve” the Harpeth’s natural floodplain as the developer stated, but alters it significantly, with extensive excavation, 6-10 feet over many acres, and down 24 feet in some areas to build up 52+ acres.  This removes most of the shallow areas that provide a critical function of slowing floodwaters down.
  • The floodplain and floodway fill proposed maximizes buildable land on the property.  It does not “improve” any flooding risk on Hillsboro Road nor for residential areas across the river from Brownland or just downriver, that now have residences in the 100-year floodplain.

3. Flooding risks are increasing in this region of the country

  • Rainstorms are increasing in intensity and frequency as witnessed in the Nashville and Franklin area in March and most recently with catastrophic flooding in Waverly and nearby areas.  The top 1% of rainiest days have increased 18% over the last 30 years! Tennessee has the highest rate of severe tornado generating storms at night, as reported in Tennessean. This increases the risk of death in this region from severe storms. 
  • Floodplain lines on a map are probabilities. They are not hard and fast features on the land like a wall or sidewalk. Floodplain lines are based on statistics that are now recognized by experts to be UNDERESTIMATING the amount of rainfall and storm intensity.  See our Conservation Conversation with experts on why flooding is increasing in this area of the country, and our blog on the Flood Factor national study that provides a user-friendly portal that presents the risk to individual properties.
  • Franklin and Nashville have many development requirements beyond FEMA’s minimum requirements. But staff have highlighted the need to review how to update these to account for the increased storms to prevent flood damage and minimize risks to public safety. 

It would be more appropriate to consider a different development concept that is NOT predominately residential to reduce flood safety concerns and consider how to reduce flood risk to adjacent residential areas now experiencing increased flooding.

  • Click here for Harpeth Conservancy analysis and comments to Planning Commission, Aldermen and staff on August 2020 and July 2021
  • Full set of latest developer proposal including city staff memos explaining reasons to recommend denial of the zoning and development plan. pages 40-196. Includes Christ Community Church.
Floodwater Depths on Roads that Provide only way in and out of Brownland Farm/Christ Community Church Development proposal: Data from FEMA, TDOT
FEMA map of 100-year floodplain (blue) and floodway (blue and orange hatched area). Black wavy lines show the flood elevation of floodwaters for 100-year floodplain (base floor elevation in feet above sea level).

A:  Hillsboro Road-  1 foot deep. 

B:   Monticello Road—4.5 feet deep

Data for both locations- Flood Insurance Study, 2/26/21.  (Harpeth River East Split Flood profile– Vol 3, p. 72)

C:  Mack Hatcher Parkway and Hillsboro Road:   Close to 2 feet in middle of intersection. 

West of intersection where Mack Hatcher is almost complete:  1.5 feet to 0.1 feet as measurements go west of Hillsboro road along the new curb up the slope. 

East of Intersection:    3.2- 2.2 feet deep. 

Click for Elevations around Mack Hatcher intersection from Eutaw.

Elevations (in feet) provided by Eutaw contractors. Base map with elevation measurement locations made by TDOT. (35 elevation measurements located in white.) HC placed elevation measurements (yellow) for some of the locations. HC approximated location of FEMA 100-year flood elevations from FEMA map above.
Harpeth Floodplain during May 2010 flood showing extensive floodplain in vicinity of Brownland Farms and Christ Community Church (just to left of the photo). Red X marks north bend on Brownland Farm. Fieldstone ball park in center, Fieldstone Farms homes in floodwaters (top right.)
Moving flood waters on Hillsboro Road by CCC (circle A on FEMA map above.) Note cars to south that are not able to drive north.

For more flooding photographs of the area see first blog on Brownland Farm development proposal.